"The Rainbow Bridge has reopened to traffic in both directions," the agency said on X.
The Buffalo Sector of the US Customs and Border Protection also said on X that the border crossing resumed operations at 6:30 p.m. local time (23:30 GMT) on Thursday.
"In coordination with @CanBorder and the @NiagaraBridges, operations have resumed at the Port of Buffalo, NY —Rainbow Bridge border crossing, today at 6:30 PM," the post said.
A vehicle exploded at the Rainbow Bridge border crossing between Canada and the US on Wednesday, leaving two people dead.
New York Governor Kathy Hochul said the incident at the border was not an act of terrorism. FBI Buffalo later said it had concluded its investigation into the explosion and turned over the case to local police as a traffic investigation since no explosives had been found and no terrorism nexus had been identified.
The Daily Mail reported Thursday that the incident had involved a $300,000 Bentley Flying Spur driven by a New York businessman.